Three men arrested over an alleged bomb threat on a plane at Heathrow were too drunk to be questioned by police yesterday.

The trio were dramatically detained when armed cops boarded the Boeing 777 moments before it was due to take off for Dubai on Friday night.

The oldest of the three was said to have made a "verbal threat" which resulted in the crew raising the alarm. A police source said the men - all thought to be British and aged 58, 48 and 36 - were still "steaming drunk" in cells yesterday and had to be left to sleep the booze off in custody. One passenger on the Emirates flight said: "They should never have been allowed on."

The plane was evacuated and delayed for 18 hours while it was searched. Nothing suspicious was found.

The scare came amid heightened tension following the Christmas Day bomb plot at Detroit.